Devices for the removal of the cut-off discard from presses



July 7, 1959 w. PlRWlTZ 2,393,551

DEVICES FOR THE REMOVAL OF THE CUT-OFF DISCARD FROM PRESSES Filed June 20, 1955 lNVENTOR N.P1L1 w (Liz United States Patent M DEVICES FOR THE REMOVAL OF THE CUT-OFF DISCARD FROM PRESSES Wilhelm Pirwitz, Ratingen, Germany, assignor to Schloeman Aktiengesellschaft, Dusseldorf, Germany Application June 20, 1955, Serial No. 516,585

Claims priority, application Germany July 8, 1954 4 Claims. (Cl. 207-1) In the operation of presses the cutting-01f of the discard from the work-piece and its removal amounts to a considerable portion of the working time. It is the pur pose of the invention to simplify this task and to accelerate it. The device for the removal of the cut-oii discard consists of a magnet, which can be swung or can otherwise be moved approximately in a plane perpendicular to the centre line of the press and can be controlled, so that it can be switched on in its position in front of the iron pressing disc to 'which the discard adheres, and switched off in a position away from the centre line of the press. Permanent magnets are employed, which are preferably arranged in a circle, with their poles alternating. The north pole of a magnet can then :be connected to the plate carrying the work-piece, or short-circuited with the south pole of the adjacent magnet by the displacement of iron or steel parts, as desired. It is particularly advantageous to arrange the magnet on a swinging arm, since it does not interfere with the work at the press in the position where it is swung upward. Moreover it is then an easy matter to provide a device which automatically switches on the magnets when the said arm is swung into the centre line of the press, and which automatically switches the magnets off when the arm is swung out and has reached a certain position away from the centre line of the press.

In order that the invention may be clearly understood and readily carried into effect, the same will now be explained more fully with reference to the accompanying drawings, in which:

Figure 1 shows a press head with a device according to the invention;

Figure 2 is a front view in the direction of the arrows II-II of Figure l; and

Figure 3 is a section along III-III of Figure 2.

The press ram 2 is in the container 1. The ferromagnetic pressing disc 3, a discard 4, of aluminium, for example, a die 5, a pressure plate 6 and a tool holder 7 are indicated in their working positions by chain-dotted lines. They are held in their working position in a known manner by means of a wedge 8, which is shown in the drawing in its clear position. In this position the tool holder 7 can be moved away to the left.

When the tool holder has been moved to the position shown in full lines, a magnetic device 9 suspended from a long lever arm 10 is swung into the position shown in the drawing, so that it stays in front of a pressing disc 3. The arm 10 is long and is pivoted at 18 at its upper end in such a way that the magnetic device 9 can be removed in a plane normal to the centre line of the press, and swung into it. 'The magnetic device 2,893,551 Patented July 7, 1959 ICC is then switched on, so that it is pulled firmly against the pressing disc 3. If the work-piece 4 is now parted from the bar 4a by means of a cutting tool 11, the pressing disc 3 with the discard is held against the magnetic device by its pull. The magnetic device 9- is now swung out, taking the pressing disc 3 and discard 4 with it, and is then switched oif in the swung-out position, which is diagrammatically indicated at 9a in Figure 2.

The magnetic device 9 is made up of permanent magnets 12a, 12b, 12c, 12d, and the like, arranged along a circle. The permanent magnets are arranged in such a way that the south pole of any of these magnets is next to the north pole of the adjacent magnet. A disc 13 is arranged in front of the magnetic device 9 and can be rotated about a trunnion 13a with respect to the disc 9. The rotation is effected by means of a hand lever 14. The disc 13, which is made of a non-magnetic material such as aluminium, contains as many iron bodies 15 as there are permanent magnets 12a to 12c. If an iron body 15 is in front of a magnet 12a, the field of the lines of force passes through the pressing disc 3, so that the pressing disc is held by the magnets. In order to switch off the field of the lines of force, each pair of adjacent magnets is short-circuited by the disc 13 being turned a little in the direct-ion of the arrow 16, so that the iron bodies 15 assume the position 15a shown in Figure 2. Then each body 15 touches simultaneously a north pole and a south pole of two adjacent magnets, so that these are now short-circuited. This will release the pressing disc.

I claim:

1. Means for removing from an extrusion press a severed discard adhering to an iron pressing disc comprising: a plate of non-magnetizable material displaceable in a plane substantially perpendicular to the axis of the press, between a position facing and close to the iron pressing disc and a position outside the press, a plurality of permanent magnets so mounted in the nonmagnetizable plate that a north pole and a south pole appear alternately, a second non-magnetizable plate so mounted on the said first non-magnetizable plate as to be slightly displaceable relatively thereto, and a plurality of iron bodies, equal in number to the said permanent magnets, so mounted in the second plate that in one relative position of the two plates each of the iron bodies is in contact with one only of the permanent magnets, whereas in another relative position of the two plates each of the iron bodies is in contact with the north pole of one permanent magnet and with the south pole of another permanent magnet.

2. Means for removing a severed discard as claimed in claim 1, the two non-magnetizable plates being circular discs, the second disc being rotatable relatively to the first about their common axis, and the magnets and the iron bodies being equally spaced around circles of the same diameter concentric with the said common axis.

3. Means for removing a severed discard as claimed in claim 1, further comprising a lever arm by which the first non-magnetizable plate is suspended, the said lever arm being angularly displaceable about a stationary axis into and out of a position in which the two plates face the head of the press.

4. Means for removing a severed discard adhering to an iron pressing disc as claimed in claim 1, wherein the 3 magnets are fixedly mounted in one plate and the iron 2,217,048 bodies are fixedly mounted in the other. 2,226,287 2,243,616 References Cited in the file of this patent 2,287,286 UNITED STATES PATENTS 2,317,270 666,196 Howe Jan. 15, 1901 2,360,928 1,336,317 Pottorff Apr. 6, 1920 2,602,223 2,143,026 Nordquist Jan. 10, 1939 2,723,375 2,179,625 Groden Nov. 14, 1939 2,728,453 2,209,558 Bing et a1. July 50, 1940 10 2,750,716

4 V Floss Oct. 8, 1940 Miller Dec. 24, 1940 Bing et a1. May 27, 1941 Bing et a1. June 23, 1942 Simmons May 18, 1943 Beechlyn Oct. 24, 1944 Pauhu July 8, 1952 Russell Nov. 15, 1955 Thweatt Dec. 27, 1955 Sangster -2 June 19, 1956 

